The present invention relates to a process for producing catalysts for their use within heterogeneously catalyzed reactions.
Those catalysts which are referred to hereafter are applied within a great number of chemical and petrochemical processes, such as oxidation, hydrogenation or dehydrogenation, but also air or off-gas purification, to mention but a few.
Nickel catalysts for example are used in many processes for catalytic hydrogenation, i.e. hydrogen transfer reactions such as:
syn-gas processing of naphtha or gaseous hydrocarbons, PA0 oxo-gas reforming (steam reforming), PA0 methanation, PA0 hydrotreating, hydrorefining, PA0 hydrodesulfurization (HDS), PA0 selective hydrogenation.
Usually nickel catalysts are used in their metallic form, fixed on a suitable carrier material, such as .alpha.(alfa), .gamma.(gamma), .theta.(theta)-alumina, SiO.sub.2.Al.sub.2 O.sub.3 and also other ceramic carriers (tablets, pellets, Raschig-rings) or also on zeolites. Usually hydrogenation catalyst contain 10 to 50 wt % NiO, which normally is deposited through impregnation techniques, which are soaking processes.
Water soluble inorganic or organic salts are normally used for impregnation of a carrier, e.g. nickel nitrate, --chloride, formiate or oxalate. In addition to these impregnation techniques also coprecipitation of mixed salt solutions is used, such as nickel together with aluminum salts, like AlCl.sub.3 or Al(OH)Cl.sub.2, described in patents U.S. Pat. Nos. 3,846,284 (J. Jaffe) and 3,846,285 (H. Beuther et al.)